Security alarm systems are widely used in all kinds of buildings. The common security alarm system adapted to install in office, warehouse, factory, or residence generally comprises a control panel, a local warning system electrically connected to the control panel to provide warning sound, a plurality of window sensors respectively mounted on all glass windows or on the ceiling or walls nearby the windows, which are connected to the control panel and would send a detecting signal to the control panel to trigger the local warning system when the respective glass window is broken, a plurality of door sensors respectively installed at all entrance and exit doors, which are electrically connected to the control panel and would send an activating signal to the control panel to trigger the local warning system when the respective door is unexpectedly opened, a plurality of motion sensors respectively installed at different motion detecting areas (monitoring zones), which are electrically connected to the control panel and would send a motion signal to the control panel to trigger the local warning system when unexpected motion is detected within the respective motion detecting area (monitoring zone), and a key pad for activating and de-activating the burglary alarm system by keying in a preset code.
In order to report the police force that a burglar may be broken into the building when the activated burglary alarm system is triggered, almost every security alarm system further comprises a phone dialing module (communicator/dialer) built in the control panel to connect with the telephone line. Therefore, when any one of the glass sensors, door sensors, and motion sensors sends a corresponding detecting signal to the control panel, the built-in phone dialing module will also be triggered to send digital signals to the central station for dispatching the predetermined police station and alarm company for help and appropriate response. Normally, the police station will immediately send closest policemen to the designated alarming building to investigate and the alarm company will try to contact the owner of the alarming building to inform the owner of the warning situation.
Theoretically, the above arrangement of the burglary alarm system is perfect if there is actually a burglar broken into the building. However, in fact, most of the situations are false alarms caused by the wrongful operation of the security alarm system by the owner. For example, if the user wrongfully sets the alarm but thinking that he or she does it correctly, when any other owner enters the building and keys in the code to de-activate the alarm system, he or she will in fact activate the alarm system, so that his or her later motion will be detected by the motion sensor to falsely trigger the warning system. The security alarm system will also be triggered and cause false alarm if any one of the detecting sensors is out of order. Generally, the motion sensor is a kind of passive infrared detector which is sensitive not only to human beings but also to all kinds of animal such as mouse and flying insect and environmental change of condition. Therefore, if there is a mouse running across a monitoring zone of a motion sensor, the security alarm system will be triggered too.
It is reported that less than 5% of the triggered alarms are caused by actual illegal events. More than 90% of the triggered alarms are false alarms caused by the motion sensors. False alarms are the unsolved troublesome to both the alarm companies and the police resources. Most alarm owners have the unpleasant experience of being waked up in mid-night by the alarm company due to false alarm. Moreover, uncountable waste of time and police force suffers most of the policemen. Before the policemen arrive at the sense, no one knows that whether it is a false alarm or an actual alarm. Therefore, the local police resource charges the alarm owner for a pretty high amount of false alarm operation fee for each false alarm and most of the users have a lot of compliant about that too. It creates a great burden to the limited police force in every city. In fact, millions expense have been wasted for the police resources in responding the false alarms, that greatly degrades the efficiency and performance of the police. Accordingly, some of the police stations in this country consider abandoning such alarm response service. It will only be good news to all burglars. Therefore, how to effectively minimize the possibility of false alarm becomes an urgent topic to both the alarm users and the police resources.
Manual verification seems to be the only solution today, that requires the operators in the central station to manually monitor the information received from the additionally installed audio and video verification equipments. However, such audio and video monitoring equipments are too expensive and will not respond automatically by themselves. Generally, the limited manpower in the central station must monitor many clients at one time, so that man made mistakes are unavoidable.